void setup() {
  // Set up port direction (set as output)
  volatile char *dir;
  dir = (volatile char *) 0x30; // Address for direction register
  *dir = 0xFF;                  // Set all pins as output
}

void loop() {
  // Main loop to output values repeatedly
  volatile char *out;
  volatile char i;
  unsigned char arr[] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F};
   
    
  for (i = 0; i < 9; i++) {      //  Correct for loop syntax
    out = (volatile char *) 0x31;  // Address for output register
    *out = arr[i];   
  delay(1000); // Send the value to the output register
  }
}